Cranfield, Cobrey and ICA seek to extend popular British asparagus season

Cranfield, Cobrey and ICA seek to extend popular British asparagus season

Gill McShane

British Asparagus Growers production

UK consumers are increasingly appreciating the benefits of eating and supporting home-grown product. The British asparagus crop is a particular summer favourite among many foodies and chefs but the season only lasts a couple of months. Thanks to a new three-year research project, however, that may be about to change. If successful, the marketing and merchandising opportunities for the classic summer vegetable could be extended, while strengthening the UK’s self sufficiency at the same time

Funded by Innovate UK, BBSRC and the asparagus industry, the £600,000 initiative is led by Cranfield University, with partners Cobrey Farms, an innovative grower which produces 30% of the UK’s asparagus crop in Ross on Wye, Herefordshire; and SME technology supplier ICA (International Controlled Atmosphere) in Kent.

The objective is to extend the British asparagus season by storing volume in a dynamically controlled atmosphere. Initial laboratory experiments have just begun, and trials will start in earnest at Cobrey Farms with next year’s crop around March/April 2016. Preliminary results are expected by August/September 2016, and the project is due to run until July 2018.

“The project is about extending the storage life of UK asparagus by up to six weeks with innovative dynamically controlled atmosphere technology usually applied to apples,” explains Professor Leon Terry, who heads Cranfield University’s Soil and Agrifood Institute, adding that his 20-strong postharvest team is one of the largest in the EU. “We are basically transferring that technology to asparagus and using some of the knowledge acquired to extend the UK season.”

Len Manning, engineering manager at ICA, explains that the SafePod system is also currently undergoing extensive trials within the UK apple industry, as reported by PBUK last month in this article.

“Effectively, what we’re doing with the help of Professor Terry is expanding the use of this technology to another produce type,” says Manning. “It’s exciting for us because it’s opening up more possibilities earlier than we thought – we were always intending to work with other products but we imagined it would come at the end of our current [apple] project.”

If it works, John Chinn at Cobrey says the project could be the “holy grail” for the asparagus industry, which is currently unable to store the vegetable for more than two to three days, meaning any overproduction results in oversupply and a drop in prices that growers are unable to recover.

“We’re investigating an idea and that doesn’t mean it’ll work, but if it does it will be fantastic – it will be a huge step forward,” Chinn explains. “We know it works with apples and blueberries, but they have a low respiration rate in comparison with asparagus.”

Satisfying home-grown demand

The UK climate means a limited and occasionally haphazard season for British asparagus, with availability starting around April 23 until early summer (June). During the eight-week harvesting window, Terry estimates that the crop totals roughly 5,300 tonnes, produced across 2,000ha, and is worth £30 million.

Asparagus consumption in the UK is rising each year during the domestic season but once that’s over the product has to be imported, with more volume arriving in July than any other month. Defra figures cited by Terry indicate that about 2,700t of asparagus are imported into the UK during July and August alone – a demand that is arguably built up by the popularity of the domestic crop in the preceding weeks.

“Part of the issue is as consumers get a taste for UK asparagus, there is demand for the domestic crop but when it’s unavailable we have to resort to buying foreign product,” Terry says.   

“If we can extend the availability of UK asparagus whilst maintaining quality, which is key, it will extend that British brand further in terms of offering a continued supply for a rapidly growing UK crop. That can only be a good thing for supermarkets and other buyers.”

According to Chinn, stocking British asparagus over imported product has “genuine” advantages for buyers. “When in season British fresh asparagus has a sugar content of 4-5%,” he explains. “For every day after harvesting that content reduces by 1% in normal air temperature. So, after three days you’re down to 1%, and then there’s no sugar left. That’s why very often eating imported asparagus is quite disappointing.

“The retailers like to support British because customers like to do so too. Plus they like to sell the best quality products. British asparagus is, and must continue to be, a better quality product. We hope [with this project] to be able to store British asparagus that still eats very well for longer. This will also give the retailers some flexibility for their marketing campaigns as we’d have the ability to hold asparagus in very good condition.”

Importantly, however, Chinn adds that British asparagus must not lose its point of difference. “It’s crucial that this project maintains the eating experience and enjoyment [of British asparagus],” he says. “That’s why we’re pleased to have the support of Tesco and Findlays [a marketing desk] in doing some tasting panels.”

Supporting self-sufficiency and the environment

By extending availability beyond June, the industry could also offset some imports of asparagus, which largely arrive from Peru during the summer, and reap the benefits of becoming more self-sufficient.

If the UK can extend its offer during the summer window, Terry says some imports could be displaced and the opportunity for sales would be lengthened. “A significant proportion of that market is available each year to UK growers through dynamic controlled atmosphere,” he suggests. “It will bring significant economic benefits to growers and packers, with volume able to rise to 7,300t; pushing up value from £30m to £41m. Just a very short increase in availability of four to five weeks could be worth about £11m.”

Terry highlights some work done by the British Asparagus Growers Association, which estimates that to import 1kg of asparagus from Peru generates about 11kg of carbon dioxide (CO2), whereas producing 1kg of asparagus in the UK releases only 2.1kg of CO2. Currently, he says, the UK imports more than 14,000t of asparagus every year – most of it by air from Peru.

As for the future of Peru’s market in the UK, Terry is quick to point out that the South American country has lots of different routes through which to sell its product. “At the moment, our primary focus is on using and deploying UK technology to benefit UK growers, rather than the knock-on effect it might have on Peruvian producers,” he says. “Peru has options to sell in other markets too.”

Besides reducing CO2 emissions, with the ability to effectively store asparagus, Terry says crop wastage would also be reduced, while new jobs would be created directly within the industry.

“The UK asparagus industry employs about two people per hectare during the season to harvest and pack,” Terry notes. “If the technology is successful, we believe it would increase employment for that sector by about 50%, which would equate to over 2,000 extra jobs during the harvesting season.”

How SafePod works

The technology functions similarly to conventional controlled atmosphere systems whereby the gases around the crop are manipulated. Ultra low oxygen (O2) levels and elevated CO2 levels are emitted to slow down the metabolic rate of the crop.

“You have to tweak the gaseous environment surrounding the crop in response to the changing physiology of that crop,” explains Terry. “Asparagus is a very challenging crop to store for extended periods of time using conventional technology because of its inherent short shelf life. It has an incredibly high respiration rate so we need various sensors to monitor and understand the changes occurring after harvest and then manipulate the atmospheric gaseous environment with the new technology accordingly.

“It’s not just a case of using the technology and suddenly having extended storage – it’s not that easy. We have to integrate the technology with science for a common outcome. It’s about not only understanding how to best deploy the technology, but it’s also dependent on us understanding the physiological and chemical processes taking place post-harvest. We need to create models of the impact of the different storage regimes on asparagus spear quality.”

Manning says Professor Terry and his team are treading on new ground with the trials. “Technology to extend the storage life of fruit is quite old in terms of reducing the O2 levels but for asparagus it’s not something the industry would particularly do. It’s groundbreaking really.”

Wider potential

If the technology proves viable for asparagus, Chinn believes the UK industry at large will benefit thanks to the collective nature of the business. “It’s a small industry and we all know each other,” he points out. “I’m sure the bigger growers would build specialised dynamically controlled atmosphere stores so there would be enough [capacity] for everyone. Anyway, it needs to be exploited by all growers in order to maximise the impact for all.”

As well as making the technology available to UK growers, if the trials are successful ICA will potentially market SafePod to asparagus producers overseas. The firm also has definite plans to develop the system for additional products beyond apples and asparagus.

“More people will probably ask what else can we use this technology for,” Manning says. “We’ll certainly look to extend it [to other fruits and vegetables] where this technology isn’t already used, but there are limitations.”

Terry believes SafePod stands “every chance” of being rolled out to other products, especially those with short seasons where there’s a demand for a UK-grown crop.

“There is lots of potential to extend this technology to other products where consumers have an affinity to buying homegrown,” he notes. “There’s definitely scope but each product has it’s own challenges. It’s very far reaching though – if it works with a product with a very short shelf-life like asparagus, and we’re confident that it will, the chances are that it’ll work with other products too.”

Read about other fresh produce projects Professor Leon Terry is involved in here.



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